Egyptian state television initially blamed the bloodshed on protesters, who it said had attacked security forces. There were also attempts to portray the violence as sectarian in nature.

But more and more people who were caught up in the violence have been coming forward to point the finger of blame squarely at the security forces, who they say employed brutal tactics to suppress the protest.

Here is the testimony of four people who were involved.

Sherief Gaber, 27, recent graduate

I joined the march because I absolutely agreed with what it was asking for – at the bare minimum some sort of recognition for the church that had been burned and some real action from the government that is claiming to have an interest in protecting minorities – and so I couldn't sit by and watch this get covered up like the last however many incidents of church burning and the like …

The vast majority were Coptic Christians protesting but there were Muslims and others there for sure, especially once the march got into downtown and once the events started to unfold …

It [the mood] was a mix both of excitement and anger. People were emboldened by the turnout. It was a very large march but they were also, you have to understand, incredibly upset – a church had been burned with kind of no recognition and furthermore the first protest that set itself in front of the TV building had been violently dispersed in a matter of hours by the army.

So people were upset but also felt encouraged by the numbers … and what these kind of numbers could bring as far as a result, pressure-wise … We were actually accosted briefly going through an underpass at the beginning of the march.

There were some stones thrown but it resolved itself fairly quickly. It seemed that wasn't a concerted effort to stop the march … We arrived in the area of the state TV building and in order to get there, there were two routes the march could take and in fact did [take], around the Ramses Hilton to get to the state TV building.

There was a short side street behind the hotel that leads to the TV building so I went with some friends. We decided to walk that route and go with the contingent of the marchers there to see the people who were already standing in front of the building.

But we hadn't even reached the building before screaming began and soldiers just came rushing at us with riot shields and batons. It was completely unprovoked from what I saw.

There were dozens of families there. There were women, children, grandparents. These were families coming out [to protest] so it was just bedlam at the beginning.

Many people were screaming, women were crying and running almost immediately and add to that the fact once the beating started with sticks, within a few minutes we started hearing gunfire which it seems like – from some of the casualties I saw – were not blank rounds.

They were live rounds being used very, very quickly. It was an incredibly violent show of force … it was chaos for a while.

It was absolutely enraging. Within a few more minutes people had moved backwards towards the Ramses Hilton, the large street in front of it and were setting up some barricades there to stay there.

But all of a sudden several of those sort of armoured personnel carriers driven by military personnel started running up and down the streets through the crowds, deliberately zigzagging and aiming at the people, which was probably one of the most horrific things I've seen, if not the most horrific thing I have seen, in this revolution so far.

At one point I saw some young kids running behind a car to avoid the armoured car which then ploughed over the private automobile to hit these people. It was barbaric. It was really, really disgusting.

It lasted for hours and hours. What brought it to an end was just [a] complete crackdown on the entire downtown area. The state TV, in addition to spreading their normal lies and propaganda, was actually calling on citizens to come down and defend the army so at one point we had a mix of army and central security forces and these "citizens", so to speak, coming and attacking us with stones, weapons, teargas.

This lasted until attrition took over and people couldn't do it any more, until everyone had been beaten out of the area.

Mos'ab Elshamy, 21, pharmacy student and freelance photographer

I joined the march as a Muslim who went in support of the Christians who were peacefully protesting against the recent destruction of a church in Aswan, which wasn't the first time in Egypt [that this had happened].

It was a very friendly and peaceful march and I went there along with a lot of Muslims to be in support of the march and what I saw was [the] army lose control and dispersing the march with horrific brutality.

I saw the army shoot at people and chase them and run over them [with] APCs [armoured personnel carriers] and their vehicles and turn a really beautifully peaceful march into a horrific massacre …

What I saw was, all of a sudden, people running away and I heard loud gunshots in the air with the army and police chasing them [protesters] in the alleyways and side streets.

Then, when we came back to the scene, they were lying on the ground and blood had been spilled and people were trying to defend themselves by throwing rocks back [at the police and army] …

The [only] … violence [by protesters] was just like … normal … just a couple … of troublemakers … But no one – as the army claimed – had machine guns or started shooting as they claimed and no one shot at the police as the state TV claimed …

It was absolutely horrific. It was something I have never seen in my life in Egypt and, to be honest, I never thought I would see such things.

Steve Nabeel, 22, computer engineering student

I started to walk from Shubra. I was not alone. I had some of my friends with me. We walked through Shubra and then we reached Maspero [the building that houses state TV].

When we reached Maspero there were 2,000 activists waiting there. We started to shout and just when we arrived we saw stones thrown. The stones were coming from the army side. After that the army started to hit protesters with sticks.

The protesters started to run away. Then it started to be like a battle. Protesters started to throw back the stones and rocks and people were running away. The army started the violence. I saw it with my own eyes.

Then two army APCs started to hit protesters, running over them. People were very scared. Then I heard that the army said on the TV that Coptics were attacking the army with guns and asked people to come down and help defend the army …

Some people came to help the army so it was people against the people and the attackers thought they were attacking only Christians but there were a lot of Muslims fighting with the Coptics against the people that the army brought … I carried bodies into a building. There were very bad injuries. There were dead people.

Colleagues from my organisation, the Egyptian Initiative for Personal Rights, had already been on the scene and started calling me to alert me there were a large number of fatalities …

By the time I arrived most of the killings through shooting and through armoured vehicles of the armed forces running over protesters had already happened but there were still clashes between the military police members from one side as well as some Muslim men who were seemingly incited by, instigated by, the state television coverage to come out and defend the Egyptian army as that's what was being said on state TV.

They were firing teargas excessively at us and both sides were also pelting stones at each other. And at different points there were some clashes between Muslims and Christians on the scene, using batons and iron pipes, and, at least in one case, a sword.

I then left the scene and went to a nearby hospital, the Coptic hospital, where we were told that most of the bodies of those killed had been sent, and we were given access to the morgue of the hospital and we counted 17 bodies.

Many of them were uncovered and clearly showed the victims had been run over by vehicles. Some of them were body parts.